Fireplace damper cone

ABSTRACT

A fireplace damper cone is constructed of three vertically stacked, C-shaped blocks cast from pumice or other lightweight rock material with internal steel reinforcement, and sealed together with mortar. The open rear end of the block assembly is closed by a rear plate of similarly cast material, and this closed assembly is supported upon side and rear plates of similarly cast material spaced outwardly of the fireplace firebox. The inner front surfaces of the bottom and intermediate blocks incline upward toward the rear, and a damper housing, supported by the upper end of the fireplace firebox, is located adjacent said surfaces, terminating at its upper end below and forwardly of the upper end of the inner surface of the intermediate block.

United States Patent [1 1 Burcham msr se t. 30, 1975 [73] Assignees: Calvin G. Banton; Stephen G.

Banton, both of Junction City, Oreg.

[ Notice: The portion of the term of this patent subsequent to Nov. 30, 1992, has been disclaimed.

[22] Filed: Aug. 12, I974 211 Appl. No.: 496,575

Related US. Application Data [63] Continuation of Ser. No. 139,785, May 3, 1971,

589,638 6/1947 United Kingdom 126/120 Primary E.\'aminel-Carroll B. Dority, Jr. Assistant E.\-aminerPeter D. Ferguson Attorney, Agenl, or FirmOliver D. Olson [57] ABSTRACT A fireplace damper cone is constructed of three vertically stacked, C-shaped blocks cast from pumice or other lightweight rock material with internal steel reinforcement, and sealed together with mortar. The open rear end of the block assembly is closed by a rear plate of similarly cast material, and this closed assembly is supported upon side and rear plates of similarly cast material spaced outwardly of the fireplace firebox. The inner front surfaces of the bottom and intermediate blocks incline upward toward the rear, and a damper housing, supported by the upper end of the fireplace firebox. is located adjacent said surfaces, terminating at its upper end below and forwardly of the upper end of the inner surface of the intermediate block.

3 Claims, 5 Drawing Figures U.S. Patent Sept. 30,1975 Sheet 1 of2 3,908,630

FIG.

FIG. 2

ALVIN J. BURCHAM INVENTOR.

U.S. Patent Sept. 30,1975 Sheet 2 of2 3,908,630

FIG. 3 5

, I ""ll.

ALVIN J. BURCHAM INV NTOR.

BACKGROUND OF THE INVENTION This invention relates to fireplaces, and more particularly to a novel damper cone therefor. 7

Fireplace damper cones heretofore have been made up by an assembly of bricks and mortar. A conventional size fireplace dampercone thus involves the assembly of at least about 300 bricks and a correspondingly larger number of mortar joints. Because of faulty construction or of mortar deterioration with time, these mortar joints represent significant sources of leakage of fire. Since it is the damper cone that is located adjacent wooden components of the fireplace and building framework, this multiplicity of mortar joints is universally recognized by fire inspectors and underwriters as a major cause of building damage and destruction by fire. Moreover, the cost of materials and the time involved in their assembly renders this type of damper cone excessively costly.

SUMMARY OF THE INVENTION In its basic concept, the present invention provides a fireplace damper cone of substantially unitary construction adapted for cooperative association with a conventional damper and firebox.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of prior damper cone construction.

Another important object of this invention is the provision of a fireplace damper'cone cast from lightweight rock material for maximum ease of transport and installation.

A further important object of this invention is the provision of a fireplace damper cone which is adapted for cooperative association with a conventional fireplace firebox and damper in such manner as to render the firebox and damper replaceable without disturbing the damper cone and flue.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary longitudinal section of a fireplace having incorporated therewith a damper cone embodying the features of this invention.

FIG. 2 is a fragmentary sectional view taken on the line 2-2 in FIG. 1.

FIG. 3 is a plan view of the damper cone illustrated in FIG. 1.

FIG. 4 is a rear elevation of the damper cone as viewed from the bottom in FIG. 3, with the back closure plate removed.

FIG. 5 is a side elevation as viewed from the right in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT For purposes merely of illustration, FIG. 1 shows components of a conventional fireplace construction. Thus, a base of concrete block or aggregate is supported upon a footing 12 and, in turn, supports the components of a fireplace firebox. The firebox is constructed of fire brick joined together with mortar, and includes a hearth'l4, back wall 16 and side walls 18. Facing brick '20 define the front opening of the firebox and are supported at the sides thereof upon the base 10 and across the upper end of the opening on an angle iron 22, in well known mannerlThe facing brick generally extends upward at least to a mantle 24, and oftentimes extends to the full height of a ceiling.

The mantle is supported by a wooden header 26 which extends horizontally across the fireplace and is supported at its opposite ends by vertical wooden studs 28. The header and supporting studs are located behind the facing brick 20 above the top opening of the fire box. Y

The rear sideof the fireplace also is formed of bricks 30 which extend upward from the footing adjacent the back wall 16 of the firebox.

Ordinarily, a grout is used to fill the space between the bricks 30 and the back wall of the firebox, and additional layers of bricks extend upward from the base 10 adjacent the sides 18 of the firebox to form with the grout fill a support for a damper cone. The latter also generallyis made of bricks arranged to form a hollow chamber which communicates the firebox with a flue supported upon the upper end of the brick cone. It is in this area of the damper cone that maximum fire hazard is experienced. i a

In accordance with the present invention, there is provided a'damper cone of substantially unitary construction which, by virtue of'its internal design and its minimization of the number of mortar joints, substantially eliminates the possibility of fire leakage. Thus, in the embodiment illustrated, the damper cone includes three vertically stacked sections 32, 34 and 36 which are, of substantially C-shape in plan view. Each of the sections is cast from pumice or other lightweight rock material, in admixture with cement and water, in manner well knownin the art. Reinforcement steel 38 is imbedded within the castings to enhance the strength of ,the latter, as will be understood. t The three castings are stacked vertically and joined together with mortar joints which integrate the sections into a unitary construction. The open rearward end of the stacked assembly is closed by a back plate 40 which is bonded to the. stacked sections by means of mortar. The cast sections preferably decrease in peripheral and internal dimensions from bottom to top, to provide an internal chamber which communicates the open upper end of the fireplace firebox with a flue 42 supported upon the upper end of the upper section 36 and back closure plate 40. The flue is surrounded by bricks 30 and 44 which form a chimney, as will be understood.

The damper cone sections and back closure plate are supported independently of the fireplace firebox, by means of side and rear support plates 46 and 48, respectively, cast of lightweight rock material, as previously described.

The inner front surfaces of the bottom section 32 and intermediate section 34 of the damper cone incline upward toward the rear. The space under this inclined surface is adapted to contain a conventional damper housing 50 which pivotally mounts a damper element 52. The open bottom of the damper housing registers with the top opening of the fireplace firebox, and the upper end of the housing is positioned forward of the upper end of the inclined surface of the intermediate section ,34. r

I As best shown in FIG. 2, the damper housing is provided with laterally projecting side flanges 54 which rest upon the upper ends of the side walls 18 of the fireplace firebox. Spacer blocks 56 are interposed between the side plates 46 and the bottom side of the lower damper cone section 32, and are extended to overlie the flanges 52. The damper housing thus is held in proper position. Heat insulation material 58, such as glass fiber, is interposed between the damper housing and the damper cone.

The front end of the damper housing is sealed against fire leakage by a mortar type grout 60 applied to the rearward side of the face brick 20 upward from the angle iron support 22 through the space between the face brick and the bottom section 32 of the damper cone.

A similar mortar type grout 62 is used to fill the space between the rear wall 16 of the firebox and the support plates 48, the upper end of the grout fill being contoured to provide a rain. trap and wind inverter, in manner well known in the art.

The damper element v52 mounted pivotally in the damper housing is movable by conventional damper control lever mechanism (not shown) between the closed position illustrated in FIG. 1, clockwise to an open position which, preferably, still is forward of the upper end of the inclined surface of the intermediate section 34. In this manner rain is prevented from being directed downward into the fireplace firebox.

The support of the damper cone assembly on the plates 46, 48 substantially independently of the firebox and damper affords the advantage of being able to replace the firebox and damper, without disturbing the damper, cone assembly. 7

By virtue of the upward and rearward incline of the inner front surfaces of the bottom and intermediate sections of the damper cone and the accommodation of the damper housing below and forwardly thereof, all flame from the firebox is directed upward and rearward toward the flue. Such flame is directed rearwardly away from the mortarjoint between the intermediate and top sections of the damper cone, thereby substantially eliminating any possibility of fire leakage outward through said mortar joint.

It will be apparent that the damper cone may be constructed as a single casting, rather than in the three sec tions illustrated, whereby to eliminate all intermediate mortar joints. The sectional arrangement illustrated is preferred, however, since each section is sufficiently light in weight as to be handled with ease by a single person. Moreover, the sectional arrangement illustrated provides only a single mortarjoint in the area adjacent the wooden header, and the arrangement of the inclined surface effectively prevents leakage, of flame outward through said mortar joint. In the sectional arrangement the sections are preferably joined together with mortar during assembly in the fireplace. However, they may be joined together preliminary to installation in the fireplace. i I

It will be apparent to those skilled in the art that various other changes may be made in the size, shape, number and arrangement of parts described hereinbefore without departing from the spirit of this invention.

Having now described my invention and the manner in which it may be used, I claim:'

1. In a fireplace having a firebox including a hearth and side and back walls supported on a base and defining front and top openings, the combination therewith a. a substantially unitary, pre-cast, hollow damper cone member overlying the firebox top opening, the inner front surface of the cone member being inclined upward toward the rear, 7

b. side and back support members mounted on the base and extending upward therefrom adjacent the outer side of the side and back walls of the firebox independently of said firebox walls,

c. the upper ends of said support members supporting the cone member independently of the firebox walls, whereby to afford replacement of said firebox walls independently of the cone member, a damper member registering with the firebox top opening and mounted on the side walls ofv the firebox under said inclined inner front surface of the cone member, whereby. to afford replacement of the damper member independently of the ,cone

member, and I e. flue means registering with the upper open end of the cone member.

2. The combination of claim 1 wherein the cone member comprises three pre-cast vertically stacked C- shaped sections joined together with mortar, and a back closure member sealing, the open back ends of the sections. v

3. The combination of claim 1 including hold-down means interposed between the cone member and side support members and engaging the damper member on the firebox side walls for securing the damper member in position.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,908,630 DATED 1 30 September 1975 INV ENTOR(S) Alvin J. Bircham, assigned to Calvin G. and Stephen G.

I I v lt rs certrfl ed that error appears m the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the terminal disclaimer Notice, the date of "November 30, 1992" should read July 30, 1991--,-

Signed and Scaled this sixth D y of January 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ofPatents and Trademarks 

1. In a fireplace having a firebox including a hearth and side and back walls supported on a base and defining front and top openings, the combination therewith of a. a substantially unitary, pre-cast, hollow damper cone member overlying the firebox top opening, the inner front surface of the cone member being inclined upward toward the rear, b. side and back support members mounted on the base and extending upward therefrom adjacent the outer side of the side and back walls of the firebox independently of said firebox walls, c. the upper ends of said support members supporting the cone member independently of the firebox walls, whereby to afford replacement of said firebox walls independently of the cone member, d. a damper member registering with the firebox top opening and mounted on the side walls of the firebox under said inclined inner front surface of the cone member, whereby to afford replacement of the damper member independently of the cone member, and e. flue means registering with the upper open end of thE cone member.
 2. The combination of claim 1 wherein the cone member comprises three pre-cast vertically stacked C-shaped sections joined together with mortar, and a back closure member sealing the open back ends of the sections.
 3. The combination of claim 1 including hold-down means interposed between the cone member and side support members and engaging the damper member on the firebox side walls for securing the damper member in position. 